Many industrial manufacturing processes depend on metal or composite structures, which utilize precision bored holes used for mounting and assembly. Often, the machined holes have precision countersinks on one or both ends of the machined hole. Such precision countersinks ensure proper fit of the receiving fastener, while preserving the structural integrity and aerodynamics of both the fastener and the underlying structure.
However, dimensional drift, such as cutter wear, surface abnormalities and minor part distortions, may cause deviations from the designed engineering tolerance of the countersinks, which necessitates frequent inspection of the countersunk surfaces by qualified technicians. The conventional methods of inspection in limited access regions include a visual inspection of the countersinks using a mirror, as well as a manual inspection using, for example, small caliper-type tools, mirrors, molding clay (e.g., by inspecting the countersink imprint on the clay), countersink depth gauges, or other means. The conventional methods of inspection, however, are time consuming and difficult to implement in confined spaces. Additionally, the countersinks generated on aircraft production parts, such as the titanium double-plus wing chord, have less than desirable accessibility since they are generated in areas of the structure that are recessed and/or located in confined space volumes. Conventional measuring devices and methods described above may not yield desirable results.
Accordingly, there is a need for systems and methods for inspecting precision countersinks in aircraft structures, where a quantifiable assessment of the precision countersinks can be performed, regardless of the location and accessibility of the machined hole surfaces.